MyVisionTest News Archive

Selective retina therapy (SRT) is a new laser procedure for retinal diseases thought to be associated with abnormality of the retinal pigment epithelium (RPE). The aim of the irradiation is to selectively damage the RPE without affecting the neural retina, the photoreceptors and the choroid. Goal of the treatment is to stimulate RPE cell migration and proliferation into the irradiated areas in order to improve the metabolism at the diseased retinal sites. SRT is performed by applying brief bursts of laser pulses from a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) to diseased retinal areas. Previous research found that SRT was not effective for dry AMD. A related technique, subthreshold diode micropulse laser treatment, has been used for central serous chorioretinopathy and diabetic macular edema.

Thirty eyes of 30 patients with central serous chorioretinopathy of at least a 3 months' duration were recruited. 14 eyes were randomised to an SRT group (Q-switched neodymium-doped yttrium lithium fluoride (Nd:YLF) laser, wavelength 527 nm, t=1.7 ?s, energy 100-370 ?J, spot diameter 200 ?m, pulse repetition rate 100 Hz,) and 16 eyes to a control group. After 3 months of follow-up, patients in the control group with persistence of subretinal fluid (SRF) were allocated to a cross-over group, treated with SRT and followed up for further 3 months. The main outcome measures were change of best-corrected Early Treatment Diabetic Retinopathy Study visual acuity (BCVA) and SRF.

At 3 months of follow-up, the mean (SD) improvement of BCVA was significantly greater after SRT than in the control group: 12.7 (7.2) versus 6.3 (8.9) letters (p=0.04). SRF had decreased significantly more after SRT as compared with that the control group: 203 (136) ?m versus 41 (150) ?m (p=0.005). In eight eyes allocated to the cross-over group, the mean BCVA had increased during 3 months of follow up before SRT by 1.4 (5.2) letters and continued to increase during 3 months following SRT by 7.4 (6.3) letters, while SRF increased by 39.5 (160.2) ?m before SRT and decreased by 151.5 (204.9) ?m after SRT. In six of the eight eyes, SRF had completely resolved 3 months after SRT.

The researchers conclude that SRT appears to expedite functional recovery and the re-absorption of SRF as compared with that in untreated controls. A larger prospective, randomised phase 3 confirmative patient study is warranted.

WHAT IT MEANS TO YOU: The search continues for a safe and effective means of speeding the resolution of acute CSC. Because most cases of acute CSC will resolve fully without intervention, it is imperative that any treatment that is undertaken have a very low risk of adverse effects. Safety-enhanced photodynamic therapy is currently the most appealing of the available treatment options for acute CSC, but is still far from ideal. Newer laser procedures such as subthreshold diode micropulse and now selective retina therapy offer very promising possibilities.